Improvement in molding-pits tor casting cylinders and pipes



R. OARTWRIGHT. MOLDING PIT FOR CASTING CYLINDERS AND PIPES.

Patented May 31, 1870.

FIGURE ND. 1.

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Letters Patent No. 103,560, (Ia-tell Zilay 3], 1870.

IMPROVEMENT IN MOLDING-FIT FOR CASTING QYLINDERS AND PIPES.

The Schedule referred to in these Letters Patent and making part of thesame Be it known that I, Ronnn'r GARTWRIGHT, of Chicago, in the countyof Cook, in the State of Illinois, have invented anew and improved Modeof Constructing Molding-Pits for Casting Cylinders or Pipes; and I dohereby declare that the following is a full and exact descriptionthereof, reference being bad to the accompanying drawing and to theletters of reference marked thereon.

The nature of my invention consists in making a mold or molds, inconnection with a shaft or pipe and tunnel, whereby I am enabled toeffect a rapid cooling of the casting, and also to supply a draught orcurrent of air, whereby the collection of gas in the mold is entirelyavoided; aiso, by building the brickwork in such a manner that the samework can be used successively, without requiring renewal for eachcasting; also, by means of the shaft and tunnel, allowing access to themold, without going down or through it.

To enable others skilled in the artto make and use my invention, I willproceed to describe its con-- struction and operation.

Figure 1 is a transverse section of pit, mold, tunnel, and shaft orpipe.

Figure 2 is plan, showing general arrangement for a number of molds inlarge circular pit.

I first construct a water-tight pit, of required dimensions, to suit thenumber of molds necessary, with a crane of suitable capacity to raiserequired weight on foundation built in the center.

0n the bottom of pit, (which Iconstruct of concrete I A,) I start a ringor wall of brick-work, B, of suitable thickness and diameter to suitsize and weight of cylinder required. This I carry up high enough toallow a man to work comfortably inside.

On one side of this circle I construct an opening, connecting with atunnel, C, said tunnel being extended to meetwith vertical shaft orpipe. D, said shaft D being made of iron or other material, with ladderfastened inside, for the convenience of passing either up or down.

Upon this ring of brick-work 'B I lay a cast-iron spider and rim, 1), ofsuitable size to receive brickwork of mold.

In the center of this spider E is fitted a shaft, F,

V perpendicular to said spider E.

0f requisite diameter I then commence a ring-wall 0f fire-brick, G, saidfire-brick work being laid in molding-loam or fire-clay, and beingpierced every two or three inches through the joints with holes aboutthreesixteenths to one-fourth inch diameter, for the purpose of allowinga free escape for the gases consequent upon all casting.

The brick-work G I carry up to the necessary height for the requiredlength of cylinder.

Upon the top of the brick-work G I place a castiron ring, H, ofsuitabledhnensions to correspond with bi ick-work.

This ring II is hcld in place by bolts I, built in brick-work G, andfastened to spider I". These cffcctually retain the mold in place, tocounteract the fracture in brick-work, due to hot metal in mold.

After mold is thus constructed, I surround it with an iron casing, J,leaving sutficient space between the brick-work and casing to allow saidspace to be tilled in with coarse cinder, well rammed down.

This casing J answers the purpose of retaining the strain upon the mold,due to head of melted iron, and the coarse cinder forms aporous medium,through which the gas is allowed to escape. to the top of the floor.

In practicc,I generally combine two molds by their respective tunnels O,with one shaft D, for the sake of economizing space in foundry.

\Vhen all is. completed as described, I fill up the large pit withmaterial well rammed, leaving only openings of the diameter of the moldsand pipes or shafts in the floor.

The shaft F Iusc as a center for striking the loam to the requireddiameter for the cylinder.

By this arrangement of parts I am enabled to use the brick-work forasuccessive number of castings, it merely being required to replace theskin-loam, forming the face of the mold for every casting, instead ofbreaking up the brick-mold, as heretofore.

In practice I have used one mold twenty-seven times successively, forcylinders weighing nine and one-half tons each.

\Vhat I claim as my invention, and desire to secure by Letters Patent,is-

' 1. The pipe I) and tunnel O, in combination with the brick-work 13,substantially as described and for the purposes set forth.

2. The spider E and shaft F, in combination with the mold G,substantially as described and for the purposes set forth.

ROBERT CARTWRIGHT.

Witnesses:

WALsoN Jones, Wu. M. Mnnnn'k.

